The first solar watch with hands (1976)

The first solar watch with hands

First

Citizen’s Crystron Solar Cell of September 1976 was the first analogue quartz watch powered by light.

The Crystron Solar Cell of 1976, model 1431-12 with calibre 8629, the solar cells set into the dial — the watch itself, from Citizen’s design archive.Photograph: Citizen Watch Co. · used with credit · Citizen Design Archive

The need: A quartz watch is only as good as its battery, and 1970s batteries needed changing every year or two. Light was free and always there.
Made by: Citizen Watch Co., Tokyo. A prototype with five fan-shaped cells was shown in 1974; the production watch went on sale in Japan in September 1976 at 45,000 yen.
What was new: Solar cells set into the dial itself, charging a small rechargeable cell that could run the watch for about two years in the dark. The hands, motor and quartz circuit were those of an ordinary analogue quartz watch.
Worth knowing: The technology was renamed Eco-Drive in 1995 and is still Citizen’s signature. Solar cells of the 1970s were thick and brittle; fitting them into a dial without breaking them was the hard part.
Where it is now: Examples survive in collections; Citizen holds its own archive pieces in Tokyo.

Historian’s noteNot the first solar watch. Roger Riehl’s Synchronar, an American digital watch, was working by 1972 and on sale by 1974. The Crystron was the first with hands, that is the first solar-powered analogue quartz watch, which is also how Citizen’s own history words it.

SourcesCitizen corporate history · Citizen Eco-Drive